Abstract
Alfalfa mosaic virus is one of the most important viruses infecting potato worldwide. Genetic comparison between Coat Protein (CP) gene of AMV isolate infecting potato in Upper Egypt (AMV-Assiut) and worldwide isolates was carried out in this study. The AMV-Assiut isolate shared similarity in CP gene ranged from 90-95 and 95-97% in nucleotide and amino acid sequences of CP gene, respectively. The AMV-Assiut shared the highest similarity with Egyptian AMV isolates (Wady Elnatron) and AMV isolate from Croatia in case of nucleotide and amino acid, respectively. Phylogenetic analysis showed that AMV isolates tend to cluster into two main groups, with additional clustering of AMV isolates in each group into two subgroups, supporting the hypothesis of existence two main strains of AMV. No clear geographical or host origin structure was found among AMV isolates.